Boat-davit for ships.



PATENTBD FEB, 10, 1903.

N. MURGHISON.

BOAT DAVIT FOR SHIPS. APPLICATION FILED APR. 19, 1902.

3 SHEETS-SHEET l F0 MODEL.

INVENTOR WITNESSES:

- ATTORNEY ms NORRIS PETERS ca. PHOTO-LITNO WASHINGTON. I c.

PATBNTED FEB. 1 0 1903.

N. MURGHISON. BOAT DAVIT FOR SHIPS.

APPLICATION FILED APR. 19, 1902.

3 SHEETS-SHEET 2.

K0 MODEL.

5 WITNESSES: INVENTQRI i" v ATTORNEY PYATENTED FEB. 10, 1903.

N. MURCHISON. I

BOAT DAVITIOR SHIPS.

APPLICATION FILED APR. 19, 1 902.

3 SHEIBTSSHBET 3.-

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INVENTOR uN \N EBY ATTORNEY m: Nomus Pcrzns co. PHOTO-LITHD.. wnsummon,u. c.

UNITED STATES PATENT OFFICE.

NEIL MUROHISON, OF NEW YORK, N. Y.

BOAT-DAVIT FOR SHIPS.

SPECIFICATION forming part of Letters Patent No. 720,274, dated February10, 1903. Application filed April 19, 1902. Serial No. 103,678. (Nomodel.)

To all whom it may concern:

Be it known that I, NEIL MURCHISON, a citizen of the United States,residing in the borough of Brooklyn, county of Kings, and city and Stateof New York, have invented certain new and useful Improvements in Boat-Davits for Ships, of which the following is a specification.

This'invention relates in general to means forlowering, raising, andhousingships boats; and the object is to provide a vessel with rockingboat-davits connected together and provided with means of operating themconveniently, whereby the boatmay be lifted from its chocks, swungoutward clear of the side of the vessel, and then lowered to the waterThe invention residesin the peculiar construction of the connectedrocking davits, the means for operating them, and the stop device whichlimits the rocking movement in both directions.

In the accompanying drawings, which illustrate an embodiment of theinvention, Figure 1 is an end view showing the boat resting in itschocks. Fig. 2 is a plan, on a reduced scale, of the same. Fig. 3 is atransverse vertical section taken between the connected davits andshowing the boat swung out and suspended. Fig. 4 is a detail view of thelimiting-stop, and Fig. 5 is a detail view of the Windlass.

A designates the deck of the vessel on which the davits are mounted, andB is the boat. On the deck of the vessel are secured two serrated ortoothed tracks or ways 1, and. on these are mounted the two connecteddavits 2 2. These davits are alike, and each has the curved form clearlyshown in the drawings-that is to say, the davit has a rounded orcircularly-convex base provided with teeth 3 to mesh with the teeth onthe fixed track 1. The davits extend upward and outward from the roundedbase, andthe two davits are rigidly tied together by a top plate or beam4 and a keel plate or beam 5. There are or may be other ties connectingtogether the two davits.

The boat Bis suspended by tackles 6 from the top plate or beam, and thefalls are led through suitable guide-sheaves 7 to ratchetwindlasses 8 onthe respective davits.

To put out the boat, the latter is hoisted to free it from its chocks 9.The davits are then rocked outward on the tracks 1, as seen in Fig. 2,until the boat swings free and can be lowered by the tackles.

In order to rock the davits, the screw mechanism illustrated isemployed. This consists of a strong frame 10, secured to the deck of thevessel, a screw 11, having collared bearings in the said frame andextending transversely of the vessel or parallel with the tracks 1, acrank 12 for rotating said screw, a traveling nut 13 on said screw andguided in said frame 10, and links 14., coupling said nut with therespective davits 2.

Fig. 1 shows the position of the parts when the boat is housed andresting on the chocks, and Fig. 3 shows their position when the boa isswung out over the side.

In order to limit and stop the movement of the rocking davits in bothdirections, the latter have each a laterally-projecting stud 15, whichengages and plays in a suitably-shaped slot 16 in the elevated sideguard 17 on the track 1. This slot 16 as herein shown has substantiallya V shape; but obviously its form will vary somewhat with its position.

The teeth on the track 1 and the convex base of the davit are hereinshown as of angular or V form; but this is not essential. They may haveany convenient or suitable form, so long as they properly fulfil therequirement, which is to compel the davit to roll properly on the trackwithout slipping.

Conveniently the sheaves or blocks 7 are swiveled to the davits, so asto adapt themselves to the fall of the tackle which leads to theWindlass, and the studs 15 are rollers mounted on a rod extending acrossbetween the davits and tying them together.

The screw 11 is shown as slightly inclined to the horizontal, beinghighest at the end next the davits; but the particular arrangement ofthe screw in this respect is not essential to the invention. Fig. 2shows the frame 10 and screw 11 situated about midway between the twodavits, the links let being bent outward, so as to couple to a tie-rod18 near the respective davits.

Obviously the invention is not restricted to the particular constructionherein illustrated, as this may be varied in some respects withoutdeparting materially from the invention.

The construction described provides a simple, efficient, andeasily-operated device and one capable of being operated in roughweather or when the ship is heeled to star board or port.

It will be noted that when the boat is seated on its chocks, as in Fig.1, a vertical plane passing through the point of suspension will passthrough the center of the boat and the center of the rounded base of thedavit Where it rests on the track 1. This disposition imparts stability.The center of the curve of the rounded base of the davit is at about thecenter of the end of the boat. (Seen in Fig. 1.)

Having thus described my invention, I claim- 1. A device for the purposespecified, comprising the toothed tracks, the connected davits havingconvex, toothed bases mounted on the said tracks, the top beam of thedavits, the chocks mounted on the convex bases of the davits, tacklesfor suspending the boat from the top beam, and means for rocking thedavits and the chocks on the tracks.

2. A device for the purpose specified, comprising the tracks, theconnected davits, curved to overhang the boat and having convex baseswhich rest on the respective tracks, means which prevent the said basesfrom slipping on the tracks, the top beam of the davits, the chocksmounted on the convex bases of the davits down near the tracks, thesuspending-tackles, and means for operating the davits simultaneously.

3. In a device for the purpose specified, the combination with thetracks, having teeth and side guards, of the connected davits havingrounded bases and teeth to gear with the teeth on the tracks, ascrew andintermediate devices for rocking the davits, and limitingstopscomprising studs carried by the davits and engaging suitably-shapedslots in the side guards of the tracks.

4. In a device for the purpose specified, the combination with the trackhaving a side guard 17, provided with a substantially V- shaped slot 16therein, of the davit having a rounded, convex base to rock or roll onsaid track, and a stud in said davit and engag ing said slot.

In witness whereof I have hereunto signed my name, this 14th day ofApril, 1902, in the presence of two subscribing witnesses.

NEIL MURCHISON.

Witnesses:

HENRY CONNETT, PETER A. Ross.

